Chemoresistive Gas Sensors Based on Noble-Metal-Decorated Metal Oxide Semiconductors for H2 Detection

Hydrogen has emerged as a prominent candidate for future energy sources, garnering considerable attention. Given its explosive nature, the efficient detection of hydrogen (H2) in the environment using H2 sensors is paramount. Chemoresistive H2 sensors, particularly those based on noble-metal-decorated metal oxide semiconductors (MOSs), have been extensively researched owing to their high responsiveness, low detection limits, and other favorable characteristics. Despite numerous recent studies and reviews reporting advancements in this field, a comprehensive review focusing on the rational design of sensing materials to enhance the overall performance of chemoresistive H2 sensors based on noble-metal-decorated MOFs is lacking. This review aims to address this gap by examining the principles, applications, and challenges of chemoresistive H2 sensors, with a specific focus on Pd-decorated and Pt-decorated MOSs-based sensing materials. The observations and explanations of strategies employed in the literature, particularly within the last three years, have been analyzed to provide insights into the latest research directions and developments in this domain. This understanding is essential for designing and fabricating highly efficient H2 sensors.